Improvement in hot-air furnaces



T. w. CHATFIELD.

Hot-Air Furnace. r

Patented March 28, 1854.

Lil] llllHH PETERS. Phumumo nphcn Washiflulun n C NITED, STATES PATENTOFF-ICE.

THOMAS 1V. OHATFIELD, OF UT IGA, NEWV YORK.

IMPROVEMENT IN HOT-AIR FURNACES.

Specification forming part of Letters Patent No. 10,700, dated March 28,1854.

To all whom it may concern:

Be it known that I, THOMAS W. CHATFIELD, of the city of Utica, in thecounty of Oneida and State of New York, have invented a new.

and useful Improvement in Hot-Air Furnaces and I do hcreby declare thatthefollowing is a full, clear, and exact description of the-con:struction and operation of the same, reference being had to the annexeddrawings, making a part of this specification, in which Figure 1 is anexterior elevation of the furnace standing within the usualdouble-walled inclosure, the front of which is here cut away. so as toexhibit the furnace. Figs. 2, 3, 4, and 5 are face views of the separatepartsof the radiators F and G, Fig. 1 ,showing theinterior thereof.

The space A B, Fig. 1, is the hot-air chamber.

a e are the issues for the heated air, andm the smoke-pipe.

H k is the cold-air chamber.

c is the door for feeding the furnace, and f that of the ash-pit.

H is the fire-pot, the ash-pit being underneath it.

The usual circular grate is located at the bottom of the fire-pot H,which is moved in the usual manner through its projecting shaft I. Allthese parts are arranged substantially in the known and usual manner.

The novelty consists in the arrangement D E D E for introducing the coldair, and in the radiators F and G for distributing the heat. The objectof this new arrangement for introducing the cold air is to confineitmore closely to the heated surfaces of the ash-pit and the lower part ofthe fire-pot H, in order the more effectually to absorb the heat ofthose surfaces. The conical inclosure E E is for this purpose thrownround the ash-pit and within a few inches thereof and extending a littleabove the bottom of the fire-pot H, as here shown.

The conductors D D receive the cold air from the chamber 0. k anddeliver it-within the inclosure E E, where it receives with greatadvantage the heat radiated from the surface of the ash-pit and bottomportion of the firepot, from whence a favorable direction is given to itin its ascent around the body of the furnace.

Each of the conductors D Dis constructed in connection with a segment ofthe conical inclosure E E. The conductors occur at several other pointsin the rear, (not here seen,) so that when they are put into the Wall,as here shown, they form the circular inclosure E E quite round theash-pit, with the exception of the space occupied by the doorway infront. They may be constructed of sheet metal or maybe cast solid, eachincluding a conductor ure, or it may be introduced at any other point inthis inclosure, as may be found convenient.

The elliptical radiators F and G successively receive the heat as itrises from the interior of the furnace, and they are so constructed asto evolve the same in its passage in such a manner as to keep it as muchas possible in contact with the outer plates of the radiators. Theyareeach formed of two semi-elliptical plates, so that when put together,the concave side of each being inward, theyform an elliptical box, asseen in the figure. A proper groove or channel is cast in the rim of thelower half to receive the edge of the upper, thus forming by the use ofashes or sand an air-tight joint.

Figs. 2 and 3 show the inside of the two halves of the radiator F, Fig.1, and Figs. 4 and 5 show the same as to the radiator G.

The orifices t a, Fig. 1, represent tubes that pass vertically throughthe radiators for the free passage of the air and to increase'theradiating surfaces. They do not communicate with the interior of thefurnace, but are for the circulation of the heated air only. They arecast in short tubes on theinside of the two opposite plates, and whenthe plates are put together these also close by a tight joint in themanner described for the plates themselves. These tubes are moredistinctly shown in the reverse faces of the separate halves of theradiators in Figs. 2, 3, 4, and 5. It will be seen that they are largerand of an oval form in the upper radiator, Figs. 4 and 5. This is forthe-purpose of meeting the expansion of the air as it becomes morerarefiedin ascending and to afford still greater surface for radiatingthe heat.

The plates shown in Figs. 3 and 5represent the lower halves of theradiators F and G, Fig. 1. They have central orifices like that seen atD, Fig. 2, for the passage of the draft air and heat from the furnacebelow. These orifices are, however, covered here by the loose irregularplates 0 0, Figs. 3 and 5. These plates are laid upon the top of smallposts cast on the under plates of the radiators, and they lie aboutmidway in theinterior space of the radiators horizontally. The office ofthese loose plates is to spread the draft air and heat as it rises intothe radiators, and to keep it as much as possible in contact with themetal plates of the radiators.

Having thus fully described the hot-air furnace with my improvementtherein, what I claim as my invention, and desire to secure by LettersPatent, is

The radiators F and G, constructed as described and for the purposesdescribed, the whole being arranged and combined substantially in themanner above set forth.

I am aware of the patents of Gordon Fox,

patented in 1843, and of G. Walker, patented

